Usually, an electronic horn reached required sound levels are driven by an electronic switch to determine whether an electromagnetic coil (106) disposed inside the horn is open or closed. Then, at least, movements of a larger flat diaphragm (i.e. mechanical soniferous apparatus (112)) instead of the actual horn ducting may help resonate the sound.
Under such circumstance, the electromagnetic coil (106) driven by the electronic switch to be open or closed at a fixed on-off ratio. However, oscillation frequency of the mechanical soniferous apparatus (112) or the like is subject to variations due to ambient environment changing. Such as ambient temperature around the mechanical soniferous apparatus (112) rising may reverse the oscillation frequency of the same. But lowering the temperature may frequent the oscillation. It leads to a mechanical problem that the mechanical soniferous apparatus (112) or the like could not be operated within thoroughly harmony resonance. Max output voice voltage of the horn (without power or the mechanical soniferous apparatus (112) resonate the sound) works out substantially a lower-than-nominal threshold voltage.
Besides, the voltage fed into the electronic horn changed also detrimentally affects the actual output voice voltage. When the voltage power source turned into high voltage output with an increased current supply to the electromagnetic coil (106)—output voice voltage is substantially raised with charging. Conversely, low voltage output reduces the current supply to the electromagnetic coil (106) with a substantially lowered output voice voltage. Further, the electronic horn is subject to induced noise, for example, such as al knurled knob collided with a gag bit in a mechanical soniferous apparatus (112) of the present invention due to a gap between them becomes too small to silent them in between.
Summed up, the electronic horn outputs sound levels is conditioned by environmental factors and voltage power source; actually still does not go with what users feel or desire.